Study On The Removal Of Pollutants By Combined Treatment Of Domestic Domestic Sewage And Acid Mine Drainage

Guizhou is rich in mineral resources,the formation of acid mine drainage during mining process and after closure caused serious damage to the surrounding water and ecological environment.At present,there are many methods to deal with this kind of wastewater,and the microbial method which is treated by sulfate-reducing bacteria is the focus of the research at home and abroad.Based on the extensive research in the early stage of the research group,this study aims to use the domestic wastewater as the carbon source for the growth of sulfate-reducing bacteria,and construct a new method of "combined treatment of domestic sewage and acid mine wastewater" to achieve the win-win objective of waste treatment.The combined treatment system is divided into two parts: the mixed reaction stage and the biological reaction stage.Through the experimental study,the following conclusions are drawn:(1)In the mixed reaction stage,the use of high concentration of domestic sewage(septic tank water)is better than lower concentration of domestic sewage(sink water)as the domestic sewage source of the combined treatment system.The mixture of septic tank and acid mine wastewater can provide a better living environment for microorganisms,and it can remove the heavy metals(except Mn)to the sediment(60%-70%).A small part of the transfer to suspended solids(30%-40%).Besides,the removal rate of iron,zinc,copper,cadmium,nickel is more than 50%.(2)In the biological reaction stage,when the volume ratio of water is 2,the removal efficiency of metal pollutants is also good.At 35 ?,the pH of the increases greatly,the utilization rate of total phosphorus and sulfate is higher.After 7 days,the concentration ofiron was 0.58mg/L,2.02mg/L,8.02mg/L,and the concentration of Mn was 0.13mg/L,0.73mg/L,1.42mg/L,at the temperature of 35?,25?,15?.The effect of removing pollutants was better when limestone was added for 2 days.(3)In the process of combined treatment processing,due to the operation of the device at room temperature,the growth of microorganisms is limited,so the removal effect of nonmetallic pollutants is relatively poor,but the metal pollutants have better removal effect.The content of manganese in the effluent is higher,and the content of copper and cadmium is lower than the detection limit.(4)The occurrence of iron in the sediments of the mixed reaction pool during the simulation was mainly in the residual state,accounting for 58.08%.Cadmium is mainly exchangeable and carbonate-bound,accounting for 89.08%.In the bioreactor sediment,all of the copper is present in the sediments in an organic form.Manganese is mainly composed of carbonate-bound,accounting for 59.50%.The migration of metals in the sediments of the mixed reaction stage is characterized by iron < copper < zinc < nickel <manganese < cadmium,and the cadmium is relatively easy to release from the sediments,causing secondary pollution and relatively stable iron.The bioassay stage is copper <zinc < iron < nickel < cadmium < manganese.The removal of contaminants in the combined treatment of domestic sewage and acid mine wastewater is a complex process involving the common or interaction of various factors,including neutralization,adsorption,coagulation,sedimentation and biological effects.